The present invention relates to filters and, in particular, it concerns a filter structure employing a stack of filter disks fully immersed within a pressure vessel.
It is known to provide in-line filtering of liquids, such as water, to remove particles down to a desired size. A common configuration for such filters is to employ a cylindrical filter screen immersed in liquid within a pressure vessel, where liquid is forced to flow outwards through the screen. An examples of such a structure is disclosed in patent publication GB 1485989. This cylindrical filter screen configuration is simple to implement, but provides relatively low filter screen area for a given volume of pressure vessel.
U.S. Pat. No. 5,855,799 proposes various more compact configurations in which a larger filter screen surface can be presented in a smaller pressure vessel volume. For example, FIG. 3 of the '799 patent presents an arrangement in which a stack of filter disks are mounted on a common axial outlet pipe within a pressure vessel.